The free digital service thing is another interesting point. You mention this:
Third, if you're using a free service and are annoyed that there are adverts, so you want to ban them, then, hello, welcome to the new improved world where this service just doesn't exist in the first place.
-- and I have to wonder, is that actually a bad thing? Should things like youtube, facebook, etc exist? Hindsight is 20/20, and it's a stretch to say that we should have banned advertisement so that these things never formed, but really, I think things would be better without them.
I think youtube is maybe the best example to consider. The question is really a technical one: is there any compelling reason why we should do all of our video sharing over the internet through a single centralized multinational corporation's monopoly? Do we need their servers to do this? I don't think we do.
If advertisements were banned and the "user-created content platform" model was basically impossible to make profitable, people would still want to share videos over the internet. The incredible usefulness of the internet would have still stimulated increases in bandwidth and networking technology. The difference is that instead of a monopoly or cartel buying up obscene amounts of server space so they can control everything, we'd probably instead have a decentralized system for these "user networks" like youtube, facebook, etc. We would probably have improved peer-to-peer protocols written and improved by academics and non-profits with the sole aim of improving usefulness (with no profit motive required), rather than closed-door research done by Google or whoever to ever expand their control and entrench their userbase which is conditional on their profit from doing so.
Sure, but then nobody could afford their internet providers charge for bandwidth, so you couldn't actually allow streaming on your own personal site. The reality would instead be that some economy-of-scale provider like Youtube would still have all the videos, except it would also charge subscriptions and charge for upload space, meaning that only cashed-up people could upload.
What I think you're missing is that it's not just digital services that grew because advertising was a thing, it's pretty much every single 20th century medium of communication as well. TV is the best analogy. You have the choice of free-to-air TV, supported by advertising, or you have the walled-garden of the cable TV companies, supported by subscriptions. Remove advertising, and traditional broadcast radio for one would be an immediate casualty, because there's no real way to charge subscriptions for broadcast radio. I guess you could argue poor people would be better off if free TV wasn't a thing, but I'd argue otherwise. TV is social literacy for a lot of uneducated people. Without free broadcast TV, then things may be even more backwards than they are now. You really think they'd be reading books if they didn't have TV? Nope. Mostly, they'd be drinking more alcohol, and driving around more looking for foreign-looking types to beat up.
Also, newspapers without advertising would face immediate collapse. To avert that, they'd raise prices a lot, which would drive down circulation numbers, but they'd focus on articles that appeal to a more wealthy select number of readers. You might argue that this collapse in readership would lead to more "small" publications taking off, but it really wouldn't. If they can't afford the New York Times, but want to read the New York Times, they're not going to throw equivalent money at some local socialist zine that's been xeroxed at your local copy shop.
The reality of an advertising ban would mean the collapse of the
mediums supported by advertising and a massive shrinking of the number of creatives who can get ahead in the market. This would not lead to somehow boosting the number of progressive voices that get heard: they're generally unprofitable but are supported for the sake of diverse voices. The thing is: the fringe voices will be the first to go in a world of walled gardens and where all content needs to be profitable. The people who'd actually thrive in such a world are right-wing billionaires with deep pockets who are able to print newspapers and upload videos at a loss, but it's paid back because there's a strong editorial bent in all their "articles" that supports whatever they're trying to manipulate the populace to believe.
Sure, you could still stick your stuff up on blogspot, but they'll start charging subscriptions too, and you'll get all of 3 readers for your content. That's why those sorts of writers go work for advertising-supported sites like the Huffington Post writing about social justice issues rather than a personal blog - because they get heard.